The present invention relates to bins for holding bulk materials, and more particularly to a portable hopper for bulk materials with internal bracing for removably mounting on a tractor trailer.
Conventional portable bins for holding/dispensing bulk materials are heavy, relatively large, relatively tall, unbraced structures. The heavy, large size of such bins is required to adequately support a loaded condition when they contain bulk material such as rock, sand or gravel. Certain of the bins are mountable on truck trailers but, due to their large size, they limit use of the trailer to transporting solely the bins, i.e. there is no room for carrying additional material.
Recently, the American Association of Highway and Transportation Engineers set certain vehicle specifications that require tractor/truck trailer beds to be about 45 feet in length for loads of approximately 80,000 lbs. The old specification required trailers to be about 32 feet in length. For certain shipping operations, it is the required additional 13 feet of length is not needed. One example of these operations is when dense/palletized product is shipped. The approximate 80,000 lb. load limit can easily be contained within about a 25-32 foot section of the newly required 45 foot long trailer.
Suppliers of bagged cement and other dense products are faced with the problem of what to do with the extra space on the trailer. One possible solution would be to place an empty portable hopper for bulk materials on the trailer. The idea is to fronthaul finished product with a lightweight portable hopper, and then backhaul the hopper loaded with bulk materials that are used as raw material for the bagged cement supplier.
Conventional bins do not provide the solution because they are constructed with large dimensions and heavy materials to meet other requirements such as being able to support the weight of a load of bulk material. The net effect is that conventional bins will not fit in the extra space on the new 45 foot trailers. An example of just such a bin is shown in U.S. Pat. No. 4,138,163 to Calvert et al. which shows a large, heavy bin that covers substantially the entire truck trailer. Calvert et al. shows non-intersecting, unconnected endwall, sidewall and roof stiffeners that are designed to add a flexural capability to the bin. Calvert et al. also shows a relatively heavy container because it states that the stiffeners are spaced apart to provide for a thicker container that will be rupture resistant.
Another representative, conventional, truck trailer-mounted bin is shown in U.S. Pat. No. 3,270,921 to Nadolske et al. Nadolske et al. shows a system for mounting several bins with bulk material on a trailer for dispensing the material downwardly through an opening in the trailer. Nadolske et al. shows a system designed specifically for multiple bins each with supporting legs and a bottom discharge outlet mounted on a semi-trailer and positionable over one of plural spouts formed in the trailer frame. To dispense material from a bin, its bottom discharge outlet must be aligned with a spout, a valve must be opened, and a complex feeder-unloader unit must be moved along a track system built into the trailer frame until it communicates with the spout. Nadolske et al. does not address the problem of structuring a single, lightweight portable hopper for the extra space on new 45 foot trailers.
Other conventional portable bins are designed for handling by forklifts by including channels formed in corresponding bottom sections solely for receiving forklift tines. Examples of such bins are shown in U.S. Pat. Nos. 2,685,398 to King, 3,083,879 to Coleman, and 3,318,473 to Jones et al.
Nowhere in the prior art is there shown or suggested to construct a portable container for bulk materials so that it may be sized small relative to a trailer bed, and therefore able to provide room for carrying other items on the trailer in addition to the loaded container itself.
Also, nowhere in the prior art is there shown or suggested to form channels in such portable containers for handling by forklifts, with such channels formed by pipes or tubes that are positioned across the inside of the hopper for reinforcing it, and for providing stop structure to block the bucket of a front end loader from extending down and in against the inside surface of the wall of the hopper while loading of the container with bulk material.
Accordingly, it is a general object of the present invention to provide a portable container for bulk materials that overcomes the drawbacks of prior art bins.
Another object is to provide such a container for removably mounting to a truck trailer, and being constructed to be sized small enough relative to the trailer bed so that other items may be co-transported with it.
Yet another object of the invention is to provide such container that is suitably lightweight for allowing removal from the truck trailer when empty via a forklift.
Another object is to provide such container with an open top for loading bulk material into it using a conventional quarry loader with bucket, and with stop structure to block the bucket of the loader from extending down and in against the inside surface of the hopper while loading bulk material.
Yet another object of the invention is to provide such container with an open top for loading bulk material into it using a conventional loader with bucket, and a rack for storing a tarp that may be positioned over the open top when a load is being transported under inclement weather conditions.
An additional object is to provide such container for removably mounting on a truck trailer that is constructed to be suitably short for allowing loading of bulk material into it through its open top by conventional quarry loaders.